none.
not applicable.
not applicable.
1. Field of Invention
The present invention relates generally to reels of the type suitable to payoff strip stock from a coil to a using station, and to rewind the used stock from the using station into a coil.
More particularly the invention relates to a reel that is uniquely adapted to save floor space in the feed line when used as a payoff reel, and in the exit line when used as a rewind reel, and which, while suitable for other uses, is particularly useful in supplying and receiving strip stock to and from a using station that draws and discharges the stock in incremental lengths.
2. Description of Prior Art
Many strip stock using stations, such as punch presses and associated feed mechanisms, draw and discharge stock in incremental lengths, moving the stock in step fashion therethrough to provide a dwell time during each cycle for the using station to operate on the stock.
In feeding strip stock to such using stations, it is common practice to maintain a loop of stock between the supply station and the using station in order to accommodate the intermittent transfer of stock into the using station. The loop provides a ready supply of material available to be drawn incrementally into the using station without encountering or the need to accommodate the supply station feed characteristics.
Reels are commonly used to supply strip stock from a coil of stock to the using station. Power-rotated reels typically include a dancer arm or other apparatus to control the rotation of the reel, and thus the speed of stock payoff from the reel as it turns, to maintain the loop of stock between the reel and the using station within pre-established size parameters. When strip stock is supplied from a coil on a non-powered reel, the loop of stock accommodates the difference in supply characteristics of the rotating reel and the intermittent draw of the using station, and eliminates the potential effect of coil inertia or reel drag on the availability of material to be drawn into the using station. In both instances, the loop of stock is provided to insure that stock is immediately available to the using station on demand. Similarly, rewinding the residual strip stock exiting the using station conventionally requires a loop of stock between the using station and the rewinding reel to accommodate the differences in operational characteristics.
Unfortunately, in many conventional feed line and exit line arrangements, these loops can require substantial floor space which correlates into rent, heating and other costs of operation.
Since it is desirable to reduce operational costs associated with a strip stock using station, there is an ever-present need to reduce the floor space that is necessary to accomplish the feeding and rewinding of strip stock to and from the using station. Thus, there is a need to provide the benefits achieved with the loops of stock in conventional strip stock feed and exit lines to and from the using station while reducing and preferably eliminating the floor space requirements conventionally associated therewith.
In addition, the material in a conventional loop of stock can jerk and whip around as the stock is drawn into the using station, particularly when drawn at a relatively high acceleration. This action can cause detrimental effects on the ability to precisely control the drawn stock length, and in severe instances, presents the potential for damage to the material or surrounding equipment and injury to personnel. To preclude the possibility of such damage or injury, and to assist in providing for consistent material length draw by the using station, it is desirable to provide a supply station that reduces the tendency for the material to respond adversely to the draw characteristics of the using station.
The general purpose of the present invention is to provide a reel for coiled strip stock that is adapted to smoothly payoff and rewind the stock to and from a using station with a substantially reduced floor space requirement as compared with the floor space associated with the use of conventional reels.
A detailed objective is to provide a reel that establishes a variable-size loop of stock generally encircling the coil, the size of the loop being responsive to the differences between the stock-supply characteristics of the reel and the draw characteristics of the using station, and thus eliminate the need for additional floor space that is conventionally required to establish the loop of stock between the coil and the using station.
Another detailed objective of the invention is to provide a pair of stock guides that are cooperative to guide the stock through the variable-size loop for a relatively smooth payout of stock from the loop to the using station.
A more detailed objective is to achieve the foregoing by providing a pair of stock guides that are mounted for movement toward and away from the coil, that are biased to a position away from the coil, and that are adapted to guide the strip stock in a loop around the coil to establish a variable-size loop that smoothly contracts towards and expands away from the coil in response to the differences between the stock-supply characteristics of the reel and the draw characteristics of the using station.
Another more detailed objective is to establish the variable-size loop of stock with the guiding assistance of the coil prior to exiting the reel to the using station.
Yet another more detailed objective is to provide the stock guides on tension arms that are mounted for swinging toward and away from the coil, for ease of providing guides with relatively large movement and for ease of adjustment of the biasing forces on the guides.
These and other objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Briefly, a reel provided in accordance with a preferred embodiment includes a rotatable support adapted to carry a coil of stock, and a pair of tension arms and associated stock guide rollers that are pivotally mounted below the coil support for swinging toward and away from the coil, are resiliently-biased away from the coil, and are positioned in adjacent quadrants oppositely of the point of payoff from the coil to guide the stock in a loop around and outwardly of the coil after payoff but prior to exiting the reel. In this instance, the stock pays-off from the top of the coil on the downstream side, travels downwardly to the first roller, turns back and travels in the upstream direction under the coil and around the second roller, turns upwardly to slidably engage the outer coil of stock on the upstream side of the coil prior to the point of payoff from the coil, and then slides along the top of the coil and on to the using station. As the using station draws stock from the reel during each material draw cycle, the tension arms and rollers are drawn toward the coil and the size of the loop temporarily decreases until the reel supplies additional stock to the loop.